1. Field of the Invention
The invention relates to a supporting disk for supporting a rotor, especially an open-end spinning rotor, having a hub ring and a supporting ring situated on the outer surface of the hub ring and made from a polymer material and having a running surface for the rotor.
The development of open-end spinning machines has resulted in a constant increase in the rotational speeds of the rotor. To meet the consequently increased and still increasing demands on the temperature resistance of the supporting disks made of a polymer material, harder and more temperature resistant material variations are being used. However, the increasing hardness of the polymer material worsens its damping properties, i.e., the damping is lower.
In U.S. Pat. No. 4,667,464, the running side of the supporting ring is provided with a circumferential groove, thereby also preventing an increase in heat in the central region of the supporting ring. The circumferential ring groove is to improve the heat dissipation, so that the danger of a heat accumulation within the supporting ring is reduced. However, this design approach does not have the desired results in every case.
An improvement is to be achieved by a specific embodiment as shown in DE 197 19 791 having two ring grooves. Although as a result of the interruption of the covering on the supporting ring""s running surface the ring grooves have a positive effect on the elastic properties of the supporting ring, they decrease the bearing surface for the rotor. This results in an increased surface pressure, so that a running surface provided with ring grooves is more significantly stressed than a cylindrical running surface without ring grooves.
Accordingly, it is an object of the invention to improve a supporting disk for a rotor such that the damping of the supporting disk that is reduced when using a harder material is compensated for or even improved, and at the same time, advantages are achieved with regard to the heating and, consequently, the temperature resistance of the supporting disk.
It is another object of the invention to improve the damping properties, in particular in the case of harder polymer materials for the supporting ring, and decrease the surface pressure and heat generation at the supporting ring covering by using the maximum possible contact surface, as well as at the same time to effectively remove the flexing work heat from the covering by increasing its surface area.
These and other objects of the invention are achieved by a supporting disk for supporting a rotor, wherein the supporting ring is provided on at least one of its axial end faces with at least one lip-shaped projection. It turns out that changing the geometric shape of the supporting ring results in significant advantages for the supporting disk.